JPS6027776B2 - Drainage and rainwater collection methods - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for collecting wastewater and rainwater, and its purpose is to collect wastewater (especially non-oil-containing wastewater) and rainwater on the premises of various facilities such as factories and use it as industrial water. It is.

Japan has long been said to be a country rich in water, but with the rapid development of industry and population growth, the amount of water used has increased, making it difficult to meet the demand with natural water alone.

For this reason, in industry, cooling water is recycled,
Treated water obtained by purifying sewage and other wastewater through biochemical treatment such as the active water sludge method is reused. The amount of water used is expected to increase year by year, so securing the amount of water used is an important issue. In order to solve this problem, the present inventors examined the relationship between water and wastewater, and researched ways to circulate and use a limited amount of raw water and to utilize rainwater.

The main object of the present invention is to collect wastewater that does not contain oil, that is, non-oil-containing wastewater and rainwater, and reuse it as water for use.

In factory wastewater measures, rainwater accounts for about 40~40% of the total wastewater volume.
It accounts for 60%, and the drainage equipment is approximately 2-2% during normal operation.
．． It is customary to install one with five times the capacity. However, according to the present invention, a portion of the rainwater is collected and used, so that the drainage equipment of the main pot can be downsized. That is, the present invention allows drainage and rainwater collected on the upper surface of the ground surface formed into a water-permeable layer to pass through the water-permeable layer, and directs the drainage and rainwater that have passed through the water-permeable layer to the lower part of the water-permeable layer. Water passes through a sand layer made of earth and sand with a low effective water content, and the purified water that passes through the sand layer is collected in a water collection basin formed of an impermeable layer material, and then collected. A drainage system characterized in that water is guided into a water intake tank disposed in the water collection basin through a permeable wall surface of the water intake tank, and the water guided into the water intake tank is pumped onto the ground surface via a pumping mechanism. and provide a rainwater collection method.

Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing an example of an apparatus used in the method of the present invention. In the figure, the flow of drainage and rainwater is indicated by arrows. First, drainage water and rainwater are collected on the upper surface of the ground surface, which is the permeable layer 5.

The thickness, strength, porosity, etc. of the layer are selected depending on the purpose. Porous asphalt concrete is preferred as the water permeable material used here. Porous asphalt concrete has a small particle diameter of 3 to 6, based on the weight of the skeleton and skeleton material.
% asphalt, generally with a porosity of 20-45%
has. Note that crushed stone is preferred as the aggregate, but sand,
Gravel *Metal particles, coke, etc. can be used alone or in combination with silk. The grain size of the bone village is preferably about 1.5 to IQ. Asphalt functions as a binding material, and various types such as straight asphalt, blown asphalt, and cast blown asphalt can be used. For example, natural or synthetic rubbers (
Particularly preferred is rubber latex. ) or epoxy resin can be mixed. If the porosity of porous asphalt concrete is less than 20%, the water permeability will be insufficient, and if it exceeds 45%, the strength will be insufficient, which is not preferable. An example of the composition of porous asphalt concrete is: 10 parts by weight of crushed willow stone with a particle size of 2.5 to 5, 6 parts by weight of filler (calcium carbonate), and 4.5 parts by weight of asphalt.
There is one with a porosity of 35%, consisting of parts by weight. On the other hand, any means for guiding non-oil-containing wastewater to a water collection pond may be used, such as providing a drainage ditch or arranging a conduit above or underground.

In this case, it is preferable to be able to adjust the amount of inflow of wastewater. After the drainage water and rainwater collected on the upper surface of the ground surface, which has been made into the permeable layer 5, passes through the permeable layer 5, an effective moisture control layer is provided below the permeable layer 5. The soil layer 4 consisting of a small amount of sand is passed through.

Such soil includes gravel, tsumugi sand, kasu sand, and tsumugi sand. By passing wastewater and rainwater through these soil layers 4, they can be used for underground self-purification by soil microorganisms.Next, the purified water that has passed through the soil layers is collected in a water collection pond 2. .

This water collection pond 2 includes factories, schools, hospitals, residential complexes, baseball fields, etc.
In addition to baseball fields, fields, sports facilities, and other various facilities will be constructed by excavating a portion of the site and installing impermeable materials above the floor plate 1. Impermeable materials include concrete, asphalt, metal plates, Synthetic resin plates, synthetic resin sheets, etc. can be used as desired, but highly flexible materials such as silt cement are preferred as they have excellent workability.The size and shape of the water collection basin should be determined as appropriate, taking into account the surrounding conditions. The above-mentioned earth and sand layer 4 is provided within this water collection pond 2, and a water intake tank 3 is also provided.

In addition, before providing the earth and sand layer 4, it is preferable to fill the periphery of the water intake tank 3 with crushed stone or gravel, gravel, and coarse sand in this order from the inside to the outside to facilitate water collection.

The surroundings of the water collection pond on the ground will be made slightly higher than the ground level by adjusting the block 6 etc.

FIG. 2 is an explanatory diagram showing details of the water intake tank 3 used in the method of the present invention.

The intake tank will be placed about 20 to 30 degrees above the bottom of the water collection basin, and the space will be filled with crushed stone or gravel. The bottom and side walls of the water intake tank are made of water permeable material 7. As the water-permeable material, the above-mentioned porous asphalt concrete is preferred.
The size and shape of the water intake tank should also be determined as appropriate, taking into account the purpose of use and other factors.If a reinforced concrete perforated pipe is used as the water intake tank, the inflow speed of water from the hole will be far, and it will be difficult to collect soil, sediment, etc. This is not desirable because the influx is unavoidable.

When porous asphalt concrete is used, water permeates through the entire surface of the wood, and the inflow speed can be adjusted as desired, and it is easy to achieve a speed of 3 G'sec or less, which was previously considered impossible.

Even if the inflow speed is slow, the inflow rate will not decrease because it can flow from the entire surface of the tank. The water thus collected in the water collection pond 2 is guided into the water intake tank 3 disposed within the water collection tank 2 through the permeable wall surface of the water intake tank.

When installing the water intake pipe 13 in the water intake tank 3, it is desirable that the installation slope be 1'500 or less and the average flow velocity at the outflow end be 0.3 m'sec or less.

It is desirable that the side wall surface of the water intake tank 3 is made of an impermeable material such as a reinforced concrete layer 8 above the lowest groundwater level to prevent intrusion of wastewater that has not been sufficiently purified. Also, for the same reason, the side walls of the water intake tank should be at least 30 skins higher than the ground surface. Next, the water introduced into the water intake tank 3 is pumped onto the ground surface via a pumping mechanism. A water pump 9 is used as such a water pumping mechanism, and the water is pumped and collected into a water storage tank or the like installed on the ground surface. The water pump 9 is preferably of an automatic level switch type, and the water intake point 10 at the tip is wrapped in a mesh-like water-permeable material (wire mesh, synthetic resin silk, etc.), and if necessary, the water intake point 10 is wrapped in a chlorine sterilization tank 1.
1 will be provided.

Additionally, a lid 12 can be attached to the husband end of the water intake tank exposed to the ground surface to improve the water pumping capacity. Although the method of the present invention can be applied to factories in various industries, it is particularly effective when applied to oil refineries, petrochemical factories, etc. In other words, since 10% of the site of a refinery or the like is regulated as a green belt, a large amount of money is required for the construction of the accompanying water sprinkling equipment. If the method of the present invention is adopted, water sprinkling equipment becomes unnecessary or can be reduced in size. This machine can also greatly reduce the amount of rainwater drainage work required. Since the water quality required for industrial water is almost the same as for drinking water, sufficient consideration is required when collecting and using non-oil-containing wastewater or rainwater.

In the present invention, since the lower layer of the permeable ground surface is a soil layer, drainage water and rainwater are naturally purified as they move downward. Furthermore, when this water enters the water intake tank, it is also purified by earth and sand. Therefore, the water pumped from the water intake tank can be fully used as industrial water.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the recovery method of the present invention, and FIG. 2 is a detailed explanatory diagram of a water intake tank used in the method of the present invention. In the figure, 2 is a water collection pond, 3 is a water intake tank, 4 is a sediment layer, and 5 is a permeable layer. Figure 1 Figure 2

Claims (1)

[Claims] 1. Drainage and rainwater collected on the upper surface of the ground surface, which is a permeable layer, is passed through the permeable layer, and the drainage and rainwater that has passed through the permeable layer is collected in a drain pipe provided below the permeable layer. The water is passed through a layer of sand and sand with a low water content, and the purified water that has passed through this layer of sand is collected in a water collection pond made of impermeable material, and then the collected water is passed through the water collection pond. Drainage and rainwater recovery characterized by introducing water into a water intake tank disposed within the water intake tank through a permeable wall surface of the water intake tank, and pumping water guided into the water intake tank onto the ground surface via a pumping mechanism. Method.